Please help.. I want to upgrade but..

Ok I have a urgent problem.
I have an Tethered Jailbroken Ipod (IDK what tethered is, but I shut it i have to do steps to put it back on) firmware 2.2.1. Since its now 3.1.2 now firmware, I would LOVE to upgrade..
But I got several issues..
I want to switch libraries from computers. My old computer is totally screwed up and I want to put the ENTIRE library on my laptop, with play count and everything.
Idk how to save cydia applications, and the lists and sources I had on it. Even winterboard I have several changes and everything perfect.. would i have to download ALLL these again!?! I have several pages of apps from [PIRACY].us. How would they go right back on my ipod? I want everything the same now, but I heard that if you upgrade it deletes EVERYTHING.. Is it worth it? Should I just not? I need serious help on how to put the songs from my ipod to the new itunes on my new laptop with ALL the right information.. please help me.. I dont want everything to be deleted. Thanks so much